1. Field of the Invention
The present invention relates to a code reading device, and more particularly, to improvement of the code reading device which optically reads a symbol code such as a bar-code or a two-dimensional code, decodes an obtained read image, and transmits a decoded result to an external device.
2. Description of the Related Art
A code reading device called a code reader optically reads a bar-code or a two-dimensional code marked on a work, generates a read image, decodes the read image, and outputs a decoded result. In general, the code reader includes an optical reading element that optically reads the code, a memory to hold the read image, a processor that decodes the read image, and a transmitting and receiving circuit that transmits the decoded result to an external device. The decoded result is transmitted to a terminal device such as a PC (Personal Computer) or a control device such as a PLC (Programmable Logic Controller) through a LAN (Local Area Network) such as Ethernet (registered trademark) or a serial communication interface such as RS-232C.
In recent years, in an image sensing type reading device which analyzes and decodes image data read from a work in units of frame, a CMOS (Complementary Metal Oxide Semiconductor) image sensor is used as an optical reading element in order to reduce production cost and power consumption. Recently, larger capacity of information amount is required due to a request to implement high resolution of a read image, so that it is necessary to speed up an image process.